Shoe sewing machine



Allg- 21, 1951 J. DILGER sHoE SEWING MACHINE Filed NOV. 16, 1949 Fig IInventor John L. ou

Patented Aug. 21, 1951 SHOE SEWING MACHINE John L. Dilger, Reading, Pa.,assignor to United fShoe Machinery Corporation, Flemington, N. J., acorporation of New Jersey Application November 16, 1949, Serial No.127,606

The present invention relates to sewing machines and is herein shown anddescribed as embodied in a machine for lasting stitchdown shoes -3Claims. (Cl. 112-34) similar to that disclosed in United States Lettersl Patent Nos. 1,864,510, granted June 21, 1932, and 1,972,023, grantedAugust 28, 1934, both upon applications of Bernard T. Leveque, in whicha straight eye pointed needle is employed with a rotary loop taker toform a chain stitch seam.

In the machines in the patents referred to, a main sewing shaft of eachmachine is disconnectably connected to the needle to enable the needleto be brought to rest out of engagement with the Work during continuedrotation of the sewing shaft. The loop taker which cooperates with theneedle in forming the stitches is mounted directly on one end of thesewing shaft so that it continues its rotation after the sewing shaft isbrought to rest. In so doing, the final loop of thread carried throughthe Work by the needle is disengaged from the loop taker. Suchdisengagement is a disadvantage if it is desired to resume sewing afterhaving brought the sewing shaft to rest, inasmuch as the final loopformed before stopping the machine will not then be enchained with therst loop in restarting it and the continuity of the seam will be broken.

An object of the invention is to provide simple and effective means forenabling a machine similar to that of the patents referred to to bebroughtv to rest reliably in the middle of a seam without causing abreak in the enchaining operations by' the loop taker. In this way, acontinuous tight seam is formed and a lasting operation momentarilyinterrupted can be resumed without possibility of irregularity resultingfrom improperly enchained stitches. A further object of the invention isto provide an attachment for existing machines of the class describedwhich is readily adapted for application to such machines in aconvenient manner without the necessity of dismantlement of themachines.

To these ends, the present invention resides in a chain stitch orsimilar class sewing machine having work clamping and feeding means, aneye pointed needle and a rotary loop taker both actuated by a mainsewing shaft, a clutch for driving the shaft and means operating instopping the machine to disengage the clutch and to disconnect theneedle during continued movement of ther sewing shaft and loop taker, inwhich a brake is provided for stopping the machine to bring the mainsewing shaft to rest without disconnecting the needle therefrom, thebrake consisting of a spring pressed plunger on a clutch actuatingcollar arranged to be rendered operative when the clutch is disengagedand inoperative when the clutch is engaged. With such arrangement themain sewing shaft may be brought promptly to rest without disconnectingthe needle from the shaft. Accordingly, the loop taker remains in properoperating relationship with the needle so that a loop of thread will notbe cast olf the loop taker in stopping temporarily without beingenchained with the succeeding loop of thread.

Other features of the invention consist in certain constructions,combinations and arrangement of parts as hereinafter described andclaimed, the advantages of which will be apparent to those skilled inthe art from the following description and accompanying drawings, inwhich Fig. 1 is a detail View in side sectional elevation of portions ofa machine embodying the features of the present invention andillustrating the manner of operation of the machine upon a stitchdownshoe;

Fig. 2 is a sectional detail View in front elevation on an enlargedscale of the needle and loop taker in the machine of Fig. 1 illustratingtheir operative relationship in sewing and Fig. 3 is a detail view ofthe brake and clutch collar of the machine illustrated in Fig. 1.

The machine of the present invention is intended for operation on astitchdown shoe having a sole 4 attached to a last 6 upon which isloosely mounted a shoe upper 8. The margin of the upper and the edge ofthe sole 4 are clamped in engagement with each other by a pair ofclamping and feeding rolls I0 and I2 acting intermittently between theformation of successive stitches to feed and pull the out-flanged marginof the upper into lasted relation with the sole 4. To secure the partsoperated upon together, a seam is formed between the bite of the rollsand the last 6 by a straight eye pointed needle I4 and a rotating looptaker I6 acting at opposite sides of the work to form a chain stitchseam. The loop taker I6 is secured to one end of a main sewing shaft I8about which the feed roll I2 rotates and the sewing shaft has a centralcrank portion 20 surrounded by a socket at the lower end of aconnectend. During operation of the machine the connections thusdescribed reciprocate the needle in proper timed relation to the looptaker, causing cooperative action of the needle and loop taker to form achain stitch seam. When the machine is stopped under normal actuatingconditions, the two bell-cranks 26 and 30 which normally move togetheras a single unit are .disconnected at a point in the final sewing cycleat which the needle is at its highest point f travel out of engagementwith the work.

The means for disconnecting the bell-crank 26 from the bell-crank 30comprises a latch 38 Yfixed to a pivot 40 rotatable ina sleeve .on aYdownwardly extending arm of .thebell-crank 38 and adapted to hook over apin 42 on a downwardly extending arm of the bell-crank 26. The latch isheld in engagement with the pin 42 vby an arm 44 secured to the pivot 40and by a spring 46 stretched between the arm and a fixed member ,in themachine. When it is vdesired todisconnect .trolled rockshaft 52rotatable in the machine frame. The arm 50 also is provided with a notchv."4 which slips over the sleeve on the bell-crank 30 when the needlebar is at the top of its stroke, thus locking the needle bar initshighest position.

The rockshaft 52 has connected to it an arm 56 fixed to one end thereofand provided with a swiveling eye 58 to which is clamped the upper endof a treadle rod 60. The lower end of `the treadle rodis pivotallyconnected to a treadle 62 fulcrumed at .64 in the frame of the machine.Betweenits ends the treadle rod is surrounded by a ,coil spring 66compressed between a perforated projection 68 .of the machine frame anda .clamp collar on the treadle rod acting to raise the treadle rodagainst its own .weight and to move the rockshaft 52 into a positionwhere the needle is disconnected from the sewing shaft. The spring 66also is constructed to overcome the force of thelatchspring 46, inaddition to raising the treadle rod and rotating the rockrShaft 52.

To start themachine in operation, the treadle 62 is depressed againstthe force of the spring 66, rocking the shaft 52, and disengaging thepin 48 from the tail of the latch 38 so that the latch yieldingly movesinto the path of oscillation of the pin 42. As soon as the sewing shaftbegins to rotate, the bell-crank 26 is oscillated and the pin 42 isengaged by the latch to reciprocate Vthe needle.

To rotate the sewing shaft I8, the shaft is surrounded by a drivingpulley 12 rotating loosely on the shaft and having an linternal conicalsurface engaged by a driven member 'I4 arranged to rotate with the shaftbut slidably mounted therein for engagement with the driving pulley. Thedriving pulley and the driven member I4 comprise a clutch actuated by aclutch collar 'i6 surrounding the hub of the driven member 'I4 and heldfrom rotation with the sewing shaft by a yoke 'I8 secured to arockshaft80 rotatable in a fixed bracket 82. The rockshaft 80 also hassecured to it a forked arm 84 through the fork of which the treadle rod60 passes. To retain the clutch members disengaged, the arm 64 is heldraised yieldingly by a compression spring 86 supported by a projectionfrom the bracket 82. Above the arm 84 on the treadle rod is a clampcollar 88 located to provide lost motion with relation to the arm 84 sothat in starting the Ina.-

without disconnecting the needle is advantageous when it is necessary toadjust manually the relationship of the upper and sole of a shoe at anintermediate point during the sewing of a stitchdown seam, particularlywhen sewing about the toe of a shoe in which diiiiculty is encounteredin Y distributing the fullness in the outflanged por- Anected thereto afriction member.

-tions of the upper. As thus far described the present machine is thesame as that of the patents above referred to.

In bringing the machine to rest without disconnecting the needle, theinertia of the parts may cause the work to be carried beyond the desiredstopping point. Frequently, the operator in his attempt to stop willrelease the treadle Vunintentionally by excessive movement beyond thepoint where the needle is disconnected from the sewing shaft. When theneedle is thus disconnected, the loop taker continues independentrotation with the sewing shaft so that when the Ymachine is restartedthe loop of the stitch formed before stopping is released from the looptaker without being enchained with the newly formed stitch. In someinstances also, the sewing shaft carried by the needle from said beak sothat, upon restarting, the loop taker may miss entirely that needle loopand cast off the loop indicated at 92 of the previous stitch withoutenchaining it.

vIn the illustrated form of the invention, the sewing shaft I8 isrestarted in its independent rotation and is brought to rest promptlyafter releasing the treadle 62 toV or beyond a midposition in which vtheneedle remains connected to the sewing shaft I8 without possibility ofreverse movement of the sewing shaft. For this purpose the clutch collar'I6 has yieldingly con- The friction member is mounted on a pair ofattened surf aces .94 on the collar to which are screwed side wings of ablock 96 provided with an offset perforated lug within which is slidablymounted a spring pressed plunger 98. The plunger 98 has a recesscarrying the friction member in the form of a button |00 arranged toengage a braking surface on a disc |02 forming a hand wheel secured tothe main sewing shaft I8.

The button |00 engages the hand wheel disc I02 when the clutch isdisengaged from driving relationship. When the clutch collar 16 isactuated to engage the clutch, the button |00 is disengaged from thehand wheel disc. To `disengage the friction button from the disc uponengagement of the clutch the forward end of the plunger 98 passesthrough a restricted opening in the block 96 and is provided with stopmeans Vcomprising a pair of check nuts |04 threaded With theconstruction described, the spring pressed plunger 98 causes thefriction button |00 to engage the hand wheel disc with a substantiallyuniform braking pressure to bring the sewing shaft promptly to rest whenthe clutch is disengaged. For this reason there is a definite responsein the action of the machine to the release by the operator of thetreadle to a mid-position. The likelihood of disconnecting the needle byeX- cessive treadle release therefore is greatly reduced. Furthermore,after the sewing shaft has been stopped, the frictional force of thebutton on the hand wheel disc prevents reverse rotation of the sewingshaft.

The application of the block and plunger to the clutch collar 16requires no other changes in the construction of the machine and fewadditional adjustments. The only requirement for effective operation ofthe braking plunger is that the spring 86 must produce a greater forcethan that produced by the yielding action in the plunger to prevent theplunger from effecting adversely the disengagement of the clutch.

The invention having thus been described what is claimed is: l

1. A chain stitch sewing machine having work clamping and feeding means,an eye pointed needle and a rotary loop taker cooperating to form a seamin the Work, a main sewing shaft, a disc on the main sewing shaft, aclutch for driving the main sewing shaft, a clutch actuating collarsurrounding the shaft, a yoke connected to the clutch collar forshifting the collar axially of the sewing shaft and for preventingrotation of the collar with the shaft and connections with the sewingshaft for actuating the needle and loop taker, in combination with aspring pressed plunger on the clutch collar arranged for engagement withthe disc when the clutch collar is actuated to disengage the clutch andfor disengagement from the disc when the clutch collar is actuated toengage the clutch.

2. A chain stitch sewing machine having work clamping and feeding means,an eye pointed needle and a rotary loop taker cooperating to form a seamin the work, a main sewing shaft, a disc on the main sewing shaft, aclutch for driving the main sewing shaft, a clutch actuating collarsurrounding the shaft, a yoke connected to the clutch collar forshifting the collar axially of the sewing I shaft and for preventingrotation of the collar with the shaft, means operating in stopping themachine to disconnect the needle from the shaft during continuedmovement of the shaft and loop taker, and a treadle rod for actuatingthe yoke and the disconnecting means, in combination with a springpressed plunger disposed on the clutch collar in parallel relation tothe sewing shaft and arranged for engagement with the disc when theclutch collar is actuated to disengage the clutch and stop means on theplunger for disengaging the plunger from the disc when the clutch collaris actuated to engage the clutch.

3. A chain stitch sewing machine having work clamping and feeding means,an eye pointed needle and a rotary loop taker cooperating to form a seamin the work, a main sewing shaft, a disc on the main sewing shaft, aclutch for driving the main sewing shaft, a clutch actuating collarsurrounding the shaft, a yoke connected to the clutch collar forshifting the collar axially of the sewing shaft and for preventingrotation of the collar with the shaft, means operating in stopping themachine to disconnect the needle from the shaft during continuedmovement of the shaft and loop taker, and a treadle rod for actuatingthe yoke and the disconnecting means, in combination with a springpressed plunger disposed on the clutch collar in parallel relation tothe sewing shaft and arranged for engagement with the disc when theclutch collar is actuated to disengage the clutch, spring means ofgreater force than produced by the spring of the plunger for actuatingthe yoke to disengage the clutch and a lost motion connection betweenthe treadle rod and the yoke to enable the clutch to be disengagedbefore the needle is disconnected from the sewing shaft.

JOHN L. DILGER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,972,023 Leveque Aug. 28, 19342,454,710 Meyers Nov. 23, 1948

